The present invention relates to a leak containment system for an underground storage tank, and more particularly, to a double-walled leak containment system, to an improved process for providing the same, and to a coating layer/textile composite useful in providing the same.
Several containment systems for underground storage tanks are available in the art. One such system involves enclosing a primary steel underground tank with a secondary steel containment jacket. The containment jacket assures that any leak from the tank will be captured in the space between the tank and the jacket. By continuously monitoring the space between the tank and the jacket, a warning of tank leakage is provided. Another system is to coat the tank with an epoxy or urethane paint, add zinc anodes to the tank, and/or put a pit liner around the tank structure.
One commercially available containment system involves wrapping the tank with a high-density polyethylene (HDPE) sheet which exhibits goods resistance to hydrocarbons and other chemicals, such that the tank is completely surrounded. The abutting ends of the HDPE sheet are heat welded together. Another available containment system involves attaching a geotextile to the bottom of an underground storage tank for its full length with double-faced tape; then wrapping a stand-off polyethylene mesh around the tank body and tying the mesh in place; and thereafter wrapping a high density polyethylene sheet around the tank.
Also known, as illustrated by U.S. Pat. No. 3,453,164 to Gursky et al, is the use of polyurethane coating compositions in preparing fuel-resistant, hydrolysis-resistant containment layers for fuel storage tanks.